Tulsa County District Attorney Steve Kunzweiler announced the charge Thursday. Officer Betty Shelby surrendered early Friday morning, was booked into the Tulsa County Jail and immediately released on $50,000 bond, the station says.

Police in Tulsa released dashcam and aerial footage, 911 calls and police radio traffic following Terence Crutcher’s shooting death on Sept. 16, showing Crutcher walking away from Shelby, who is white, with his arms in the air.

Crutcher’s twin sister, Tiffany Crutcher, said Thursday her family is grateful to Kunzweiler’s office for bringing the charge. She said her mother broke down when she learned of the charging decision.

However, Tiffany Crutcher said her family is “preparing to go to war” and will push for a conviction.

“While we are pleased to learn the officer who senselessly killed by beloved twin brother will face criminal charges for her reckless act, we understand nothing will bring him back,” Crutcher said. “Nothing will bring back our father, our son, our brother, our nephew, our cousin.”

She said the family is focusing on celebrating Terence Crutcher’s life and will push for increased transparency and accountability from law enforcement.

The footage does not offer a clear view of when Shelby fired the single shot that killed Crutcher. Her attorney has said Crutcher was not following police commands and that Shelby opened fire when the man began to reach into his SUV window.

But Crutcher’s family immediately discounted that claim, saying the father of four posed no threat to the officers, and police said Crutcher did not have gun on him or in his vehicle. Family attorneys have said the vehicle’s window was rolled up, and he wasn’t reaching inside.

Though Crutcher was wearing baggy clothes, Shelby didn’t see any weapons or bulges indicating he might have a weapon, the investigator wrote.According to an affidavit filed by the chief investigator for the Tulsa County District Attorney’s Office, Shelby “reacted unreasonably by escalating the situation from a confrontation with Mr. Crutcher.” Though the investigator said Crutcher wasn’t responding to verbal commands, he said Shelby ”became emotionally involved to the point that she over reacted.”

Shelby, who joined the Tulsa Police Department in December 2011, was en route to a domestic violence call when she encountered Crutcher’s vehicle abandoned on a city street,straddling the center line. Shelby did not activate her patrol car’s dashboard camera, so no footage exists of what first happened between the two before other officers arrived.

The affidavit says Shelby initially approached the vehicle and cleared the driver’s side front before moving around to the passenger side. That’s when she encountered Crutcher, who was walking toward her, and asked him if the car belonged to him and if it was disabled. Crutcher was mumbling to himself and wouldn’t answer Shelby’s questions, the document says.

Crutcher kept putting his hands in his pockets, and Shelby ordered him to show his hands, police say in the affidavit. Crutcher then began walking away towards the vehicle with his hands in the air, not responding to Shelby’s orders to stop, the document says.

At that point, Shelby pulled out her service weapon and followed Crutcher to the vehicle. She pointed it at him, and another officer arrived and told Shelby he had his Taser ready, according to the affidavit.

That’s when, police say, Crutcher reached into the driver’s side front window, and the officer fired his Taser and Shelby fired her weapon, striking Crutcher.

The police footage shows Crutcher approaching the driver’s side of the SUV, then more officers walk up and Crutcher appears to lower his hands and place them on the vehicle. A man inside a police helicopter overhead says: “That looks like a bad dude, too.Probably on something.”

The officers surround Crutcher and he suddenly drops to the ground. A voice heard on police radio says: “Shots fired!” The officers back away and Crutcher is left unattended on the street for about two minutes before an officer puts on medical gloves and begins to attend to him.

Shelby later told police she was in fear for her life and thought Crutcher was going to kill her, the document says.

Among the definitions in Oklahoma for first-degree manslaughter is a killing “perpetrated unnecessarily either while resisting an attempt by the person killed to commit a crime, or after such attempt shall have failed.”If convicted, Shelby could face a minimum of four years in prison.

“The tragic circumstances surrounding the death of Terence Crutcher is on the hearts and mind of many people in this community,” Kunzweiler said. “It’s important to note that despite heightened tensions which seemingly beg for an emotional response and reaction, our community has demonstrated a willingness to respect the judicial process.”

In a statement, Oklahoma governor Mary Fallin said she hopes the decision brings peace to Crutcher’s family, but urged the community to be patient as the case works its way through the justice system and remember that Shelby is innocent until proven guilty.

“No matter how you feel about the prosecutors’decision in this case, I hope Oklahomans will respect the views of your friends and neighbors because we still have to live peacefully together as we try to make sense of the circumstances that led to Mr. Crutcher’s death,” Fallin said.

Fallin complimented Tulsa’s police chief, mayor, district attorney and citizens for helping to keep peace and order “during this difficult time.”

Earlier this year, a former volunteer deputy with the Tulsa County Sheriff’s Office wassentenced to four years in prison after he was convicted of second-degree manslaughter in the shooting death of Eric Harris.